[patch] Move dominance info to struct control_flow_graph

[Zdenek Dvorak <rakdver at kam dot mff dot cuni dot cz>]

Hello,

this patch moves two global variables related to the dominance
information (dom_computed, describing whether dominators were
computed; and n_bbs_in_dom_tree, containing number of basic blocks
in the dominance tree) to struct control_flow_graph.  This seems to be
the appropriate place, since all the dominance information is stored in
cfg.  This change allows to have dominance information computed for
several functions at once (which might be useful for ipa passes).

Bootstrapped & regtested on i686.

Zdenek

	* dominance.c (dom_computed, n_bbs_in_dom_tree): Removed.
	* function.h (dom_computed, n_bbs_in_dom_tree): New macros.
	* basic-block.h (struct control_flow_graph): Added x_dom_computed
	and x_n_bbs_in_dom_tree fields.

Index: dominance.c
===================================================================
*** dominance.c	(revision 126869)
--- dominance.c	(working copy)
***************
*** 48,56 ****
  #include "pointer-set.h"
  #include "graphds.h"
  
- /* Whether the dominators and the postdominators are available.  */
- static enum dom_state dom_computed[2];
- 
  /* We name our nodes with integers, beginning with 1.  Zero is reserved for
     'undefined' or 'end of list'.  The name of each node is given by the dfs
     number of the corresponding basic block.  Please note, that we include the
--- 48,53 ----
*************** static void calc_idoms (struct dom_info 
*** 126,134 ****
  void debug_dominance_info (enum cdi_direction);
  void debug_dominance_tree (enum cdi_direction, basic_block);
  
- /* Keeps track of the*/
- static unsigned n_bbs_in_dom_tree[2];
- 
  /* Helper macro for allocating and initializing an array,
     for aesthetic reasons.  */
  #define init_ar(var, type, num, content)			\
--- 123,128 ----
Index: function.h
===================================================================
*** function.h	(revision 126869)
--- function.h	(working copy)
*************** extern int trampolines_created;
*** 535,540 ****
--- 535,542 ----
  #define nonlocal_goto_handler_labels (cfun->x_nonlocal_goto_handler_labels)
  #define rtl_df (cfun->df)
  #define current_loops (cfun->x_current_loops)
+ #define dom_computed (cfun->cfg->x_dom_computed)
+ #define n_bbs_in_dom_tree (cfun->cfg->x_n_bbs_in_dom_tree)
  #define VALUE_HISTOGRAMS(fun) (fun)->value_histograms
  
  /* Given a function decl for a containing function,
Index: basic-block.h
===================================================================
*** basic-block.h	(revision 126869)
--- basic-block.h	(working copy)
*************** enum bb_flags
*** 349,354 ****
--- 349,363 ----
  #define BB_COPY_PARTITION(dstbb, srcbb) \
    BB_SET_PARTITION (dstbb, BB_PARTITION (srcbb))
  
+ /* State of dominance information.  */
+ 
+ enum dom_state
+ {
+   DOM_NONE,		/* Not computed at all.  */
+   DOM_NO_FAST_QUERY,	/* The data is OK, but the fast query data are not usable.  */
+   DOM_OK		/* Everything is ok.  */
+ };
+ 
  /* A structure to group all the per-function control flow graph data.
     The x_* prefixing is necessary because otherwise references to the
     fields of this struct are interpreted as the defines for backward
*************** struct control_flow_graph GTY(())
*** 381,386 ****
--- 390,401 ----
      PROFILE_GUESSED,
      PROFILE_READ
    } x_profile_status;
+ 
+   /* Whether the dominators and the postdominators are available.  */
+   enum dom_state x_dom_computed[2];
+ 
+   /* Number of basic blocks in the dominance tree.  */
+   unsigned x_n_bbs_in_dom_tree[2];
  };
  
  /* Defines for accessing the fields of the CFG structure for function FN.  */
*************** enum cdi_direction
*** 888,900 ****
    CDI_POST_DOMINATORS = 2
  };
  
- enum dom_state
- {
-   DOM_NONE,		/* Not computed at all.  */
-   DOM_NO_FAST_QUERY,	/* The data is OK, but the fast query data are not usable.  */
-   DOM_OK		/* Everything is ok.  */
- };
- 
  extern enum dom_state dom_info_state (enum cdi_direction);
  extern void set_dom_info_availability (enum cdi_direction, enum dom_state);
  extern bool dom_info_available_p (enum cdi_direction);
--- 904,909 ----